This is tough for me as I have several that are pretty high on my favorites list. My top 3 are
"It has been said, 'time heals all wounds.' I do not agree. The wounds remain. In time, the mind, protecting its sanity, covers them with scar tissue and the pain lessens. But it is never gone."
"If people are good only because they fear punishment, and hope for reward, we are a sorry lot indeed." Albert Einstein
"Give a man a fish and he will eat for a day; teach a man to fish and he will eat for a lifetime; give a man religion and he will die praying for a fish."
Quote from Unknown